Crop Culture Report: Under the Sea Coleus By Jessica DeGraaf

One of the most unique new introductions in the past year, the Under the Sea Coleus collection from Hort Couture has a unique subset of leaves that make them resemble the most intricate of sea creatures. From the diminutive 'Red Coral' and 'Molten Coral' to the huge lobed leaves of 'Langostino' and 'Hermit Crab', these sun and shade loving plants will add texture, color and pizzazz to any container garden.

Bred by undergraduate students at the University of Saskatchewan, the Under the Sea collection offers an eye-catching assortment of foliage shapes and colors that are perfect for mixed combinations or landscape applications.

The Under the Sea Collection consists of eight varieties that are each arrestingly different in their habit, leaf structure and coloration.
'Bone Fish': Compact grower with deeply divided leaves that are red with golden edges.

'Gold Anemone': Large, lush grower with leaves typical of the collection with pronounced secondary leaflets. Leaves are gold with hints of purple edging.
'Hermit Crab': Medium sized grower with bright pink crustacean-shaped leaves with lime green edging.
'Langostino': Largest grower in the collection. Orange-red leaves with large secondary leaflets that are edged in
bright gold.
'Lime Shrimp': Medium grower with unique elongated leaf structure. Each leaf is lime colored with strong purple overtones
and edging.
'Molten Coral': Compact grower with amazing red-orange color and bright green tips.
'Red Coral': One of the most compact in the collection with duckfoot, congested leaves that are red with green and black edging.
'Sea Scallop': Medium grower with rounded chartreuse leaves with strong purple edging and overtones.


Media and pH: Under the Sea coleus require a well-drained, soilless media with a pH of 5.8 to 6.2. Liners should be kept moist upon transplant, but they should not be oversaturated. Once liners have sufficiently rooted out, begin to allow the media to dry down between irrigations.

Temperature and daylength: To promote optimum growth, provide high light levels, moderate temperatures and negative DIF. Maintain day temperatures of 70 to 80¡ F and night temperatures of 60 to 70¡ F. Under the Sea Coleus respond well to high light levels. Maintain light levels of 4,000 to 5,000 foot-candles to promote best growth while maintaining moderate temperature levels. Note that low light levels result in poor branching, stem stretch and poor foliage color.

Fertilizer: The Under the Sea collection requires a moderate amount of fertilizer. A constant application of a balanced nitrate-based form fertilizer promotes optimum growth. Apply at rates of 150-200 ppm. Avoid overfeeding with ammonium-based fertilizers and high application rates as this causes stretched, weak growth. Leach regularly to avoid the buildup of soluble salts in the soil.

Growth regulation: The Under the Sea Collection has a fair amount of variation in size between cultivars. Most are naturally compact and require very little pinching or PGR application. However, some of the more vigorous types do benefit from a pinch applied one to two weeks after transplant. A second pinch can be applied to shape as desired. If growers prefer, the following growth regulators have been found to be effective B-Nine at 2,500 to 3,500 ppm, Cycocel (1,000 to 1,500 ppm) and Sumagic (5 to 10 ppm).

The more vigorous growers in the series are: 'Gold Anemone', 'Langostino', 'Lime Shrimp' and 'Sea Scallop'. These varieties may require an additional pinch or PGRs to control growth.

Pests and Diseases: If good cultural practices and IPM techniques are applied, the Under the Sea collection should not have issues with pests and diseases. Scout for aphid, fungus gnat and whitefly.

Crop Timing from Transplant
41/2-inch pot: four to six weeks
6-inch pot: five to seven weeks

Crop Culture Report: Under the Sea Coleus

Jessica DeGraaf

Jessica DeGraaf is product manager for Hort Couture. She can be reached at [email protected]

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